Shortly after the storming of the citadel of the insurrectionists, several respectable looking citizens of Harper’s Ferry approached Major Warner excitedly, and declared that a large number of the insurrectionists, under the command of J. F. Cook, one of the leaders of the rebellion, had entrenched themselves within an unoccupied log cabin, sometimes used as a school house, and had fired upon certain citizens a few moments before; and the assistance of Major Warner was asked to dislodge them. The latter replied that his corps being under the command of General Egerton he could not act without orders from him, but that they were eagerly willing to volunteer for the service. Meantime Gen. Egerton having received intelligence to the same effect as that communicated to Maj. Warner, had detailed the Independent Greys, Lieut. Simpson, to dislodge and capture the party.

The gallant Greys proceeded at “double-quick” time, along a constantly ascending and rocky road to execute the order. About a mile from the Ferry, they arrived within sight of the school house, a cabin situated in a gloomy hollow, and, apparently, closely barricaded. Halting for a few moments, the Greys formed into two platoons, under the respective commands of Lieut. Simpson and Kerchner, and, at a given signal, dashing down the declivity of the road, with the butt end of their muskets, battered in the doors and windows, through which they entered. The cabin was entirely empty of occupants, though on all sides were discovered evidences of recent occupation, and a hasty retreat of its inmates.

Against the front door were piled sixteen long and heavy boxes, one of which—upon being burst upon—was found to contain ten newly finished Sharp’s breech loading rifles, evidently fresh from the hands of their maker. There was also discovered one large square box, exceedingly heavy, which was suffered to remain unopened; a large and heavy black trunk, a box filled with bayonets and sabers, and several boxes of rifle cartridges and ammunition. There were in all 21 boxes, several of which were filled with Maynard’s large—sized patent revolvers, with powder flasks accompanying.

The room was littered with Sharp’s rifles, revolvers and pikes. Evidently distributed with a view to their immediate use, either for the purpose of defense or an aggressive action. After satisfying themselves that the traitors had fled, the gallant Greys proceeded to possess themselves—each man—of a rifle, and a pair of revolvers, the remainder being placed together with a large number of pikes, &c., upon a large new wagon (purchased but a few days before by Smith, or Capt. Brown as he is now known,) to which the captors harnessed a pair of fine horses they caught grazing in the enclosure, and conveyed their valuable prize into town, where they were received with loud cheers by the citizens and military.

The captured boxes were placed for safe keeping in the Arsenal of the United States, though the Greys asserted an exclusive right to their possession as the lawful prize of its captors.

The revolvers and rifles were entirely new, and evidently expressly manufactured for the insurrectionists, the initials of whose leader’s name, “J. F. C.,” were stamped upon every weapon.

The boxes in which the weapons were contained were marked thus, “By railroad via Pittsburg and Harrisburg. J. Smith & Sons, Chambersburg, Pa. By American Express Company. Keep dry.”—One box was directed to “W. F. McClarney, Marine Bank Building.” The name of the town had been obliterated, but several legible letters indicated that Cincinnati was the place. One small box, containing cartridges, was inscribed with the initials “J. B.,” written on the back of a nearly obliterated card, with the following printed advertisement, “From Burr and Swift, wholesale and retail dealers and importers of groceries,--, fish, fruit, tobacco, segars,--, glass, salt, rope, wooden-ware, etc.; commission and forwarding merchants,--between Front and Second, Davenport, Iowa.”-- Another unopened box, supposed to contain rifles was addressed to “T. B. Eldridge, Mt. Pleasant,--.” The succeeding portion of the address, the name of the State perhaps, had been carefully obliterated.

DISCOVERY OF THE PAPERS OF THE INSURRECTIONISTS.

The excitement attending this clever exploit had scarcely subsided, when another alarm was given, that the notorious insurgent leader Cook, had a few minutes before been seen upon the mountains on the Maryland shore.

A scouting party consisting of several members of the Greys,- (the only foreign corps in the town, quite or nearly all of those present in the forenoon having left for their homes,) some score or more of volunteers, and about twenty U. S. Marines under command of Capt. J. E. B. Stewart, was instantly formed, and proceeded rapidly in pursuit.

Following the same path which the Greys had pursued in making their discoveries, and which is known as the “County road,” leading into the heart of Washington County, Md. the party continued their course for a distance of 4 1/2 miles from the Ferry, until they reached the farm and house brought and occupied by Brown, under the name of John Smith. The dwelling, a log house, containing two unpaved basement rooms, used apparently for storage, and in which were several empty gun boxes; two rooms and a pantry upon the second floor; and one large attic room in which were about six husk mattresses—was discovered to be unoccupied, save a huge, savage looking mastiff, tied with a rope to the railing of a small piazza outside the house, but there were abundant evidences of it recent hurried vacation. The floors of all the rooms were littered with books, papers, documents and wearing apparel of several persons, hastily snatched from eight or ten trunks and an equal number of valices and course carpet bags, strewed around, the fastenings of all of which had been forcibly broken, as if their violaters were too much hurried for time to adopt the tardier method of entrance, by looking up keys. In the pantry, which appeared to have been used for kitchen purposes, beside an almost new cooking stove and an abundance of tin utensils, were two barrels of flour, a large quantity of sausage meat and cured hams, together with several pounds of butter, lard, &c.—The fire was yet smouldering in the stove, and the water in the boiler was quite hot at the time of the entrance.

But the most valuable discovery was a trunk belonging to Capt. Brown, containing a great number of highly important papers, documents, plans, and letters from private individuals throughout the Union—all revealing the existence of an extensive and thoroughly organized conspiracy, whose leaders were Captain Brown and J. T. Cook, and the well defined, determinedly expressed object of which, was the hastening of “irrepressible conflict” predicted by Senator Seward, and recently by Gerrit Smith, which was to result in the “disenthralment of the slaves of the South,” and the extinction of the “Slave Power.”

The Hon. Henry A. Wise, Governor of Virginia, has established his quarters in the hotel at Harper’s Ferry, and is extending his investigation of the insurrection in every direction. Witnesses were being hourly brought before him and the most alarming proof of a formidable plot was being gradually traced out. Parties of scouts on horseback, and accompanied by hounds, had gone to the mountains in search of others of the implicated parties, and for the purpose of recapturing any parties of slaves that might be found making their way into the free States.

The Governor is aided in his investigations by District Attorney Ould, of Washington, who has prepared the papers necessary for the commitment to jail of those of the insurgents captured. The following is the only correct list of the insurgents killed and captured, both black and white, with their nativity and places of residence.

Old Gen. Ossawattomie Brown and Aaron C. Stevens are still alive. They lie in their beds guarded, and none but the surgeons and attendants are allowed to enter the rooms.

Brown has nine wounds, and Stevens three wounds on his person. Edwin Coppee is unhurt; and with the negro Copeland was yesterday taken to the jail at Charlestown, Va. Emperor, also negro, is in chains at Harper’s Ferry.

These five are the miserable remnant of the fanatical band.

THE GOVERNOR’S INTERVIEW WITH OLD BROWN;

Yesterday morning Gov. Wise, accompanied by District Attorney Ould and several others, visited this remarkable man in his bed room. Brown was propped up in his bed, evidently suffering great pain from his numerous wounds, but with his mind collected, and looking calmly about him, now and then giving vent to a groan. The Governor, after questioning him several times, got him into a talking mood, and he voluntarily made the following important disclosures:

“I rented the ‘Kennedy Farm’ from Dr. Kennedy, of Sharpsburg, Washington county, Md., and named it after him. Here I ordered to be sent from the East all things required for my undertaking. The boxes were double, so no one could suspect the contents of them, even the carters engaged in hauling them up from the wharf. All boxes and packages were directed to J. Smith & Son. I never had more than 22 men about the place, but I had it so arranged that I could arm, at any time, 1,300 men with the following arms: 200 Sharpe’s rifles; 200 Maynard’s revolvers, 1,000 spears and tomahawks. I would have armed the whites with the rifles and pistols, and the blacks with the spears, they not being sufficiently familiar with the other arms.

“I had plenty of fixed ammunition and enough provisions, and had a good right to expect the aid of from 2,000 to 5,000 men at any time I wanted. Help was promised me from Maryland, Kentucky, North and South Carolina, Virginia and Canada.—The blow was struck a little too soon. The passing of the train (Phelps, on Sunday night,) did the work against us—that killed us. I should not have let it pass. But I only regret I have failed in my designs, but I have no apologies to make or concessions to ask now. Had we succeeded, when our arms and funds were exhausted by an increasing army, contributions would have been levied on the slaveholders and their property appropriated to defray expenses, and carry on the war of freedom. Had I known government money was in the safe here I would have appropriated it.”

Old Brown here appeared quite exhausted, and leaned back in his bed, looking calmly around.—Gov. Wise told him he had better be preparing for death, to which Brown responded that he (the Governor) though he might live fifteen years, would have a good deal to answer for at last, and had better be preparing now too.

The following is a copy of the anonymous letter sent to the Hon. Secretary of War, from Cincinnati, some two months since, and which affords a clue to the mystery of the insurrection at Harper’s Ferry:

CINCINNATI, August 20

“Sir:--I have lately received information of a movement of so great importance that I feel it to be my duty to impart it to you without delay.

“I have discovered the existence of a secret association having for its object the liberation of the slaves of the South by a general insurrection.—The leader of the movements is ‘Old John Brown,’ late of Kansas. He has been in Canada during the winter, drilling the negroes there, and they are only waiting his word to start for the South to assist the slaves. They have one of their leading men (a white man) in an armory in Maryland; where it is situated, I am not enabled to learn.

“As soon as everything is ready, those of their number who are in the Northern States and Canada are to come in small companies to their rendezvous, which is in the mountains of Virginia.—Brown left the North about three or four weeks ago, and will arm the negroes and strike a blow in a few weeks, so that whatever is done must be done at once. They have a large quantity of arms at the rendezvous, and are probably distributing them already. I am not fully in their confidence. This is all the information I can give you. I dare not sign my name to this, but trust that you will not disregard this warning on this account.

The Baltimore Sun says that the Governor expressed his mortification at the disgrace which had been brought upon the State. He would rather have lost both legs and both arms from his shoulders and hips than such a disgrace should have been cast upon it, that fourteen white men and five negroes should have captured the government works and all Harper’s Ferry and have been able to retain them for one hour. Col. Lee, with twelve marines, settled the matter in ten minutes. That nineteen men should capture one hundred prisoners was something like the policeman who captured ten men, and said “Faith, I surrounded them.” They should read Shakspeare and study Falstaff’s oaths. A prisoner remarked that there were ten of them [laughter] prisoners, and nine insurgents, but that the latter were each armed with three Sharp’s rifles and two Colt’s revolvers. “We were,” said he, “huddled in like a flock of sheep.” “Yes, said the Governor, “you were in a corner, and you were very much like sheep. They certainly cornered all Harper’s Ferry."